Desperate for rest in a frenzied world, at least 8.6 million Americans take prescription sleeping pills to catch some Zzzs, according to the first federal health study to focus on actual use.

Between 2005 and 2010, about 4 percent of U.S. adults aged 20 and older popped popular prescription drugs such as Lunesta and Ambien in the previous month, say government researchers who tracked 17,000 people to their homes and peered into their medicine cabinets.

About a quarter of those studied suffered sleep problems serious enough to report to their doctors, said Yinong Chong, an epidemiologist with the Centers for Disease Control and Prevention.

“They told us they had difficulty getting to sleep, or they were waking up and couldn’t get back to sleep,” said Chong, whose study is based on data from the National Health and Nutrition Examination Survey.

The report provides the latest evidence that a good night’s sleep is becoming more elusive. In 2008, market research from Thomson Reuters found that sleeping pill prescriptions had tripled among people younger than 45. The new study offers the first look at how many people are actually taking them, Chong said.

Overall, between 50 million and 70 million Americans suffer from sleep disorders or sleep deprivation, according to the Institute of Medicine, which advises public policy. Adults typically need between seven and nine hours of sleep a night, but more than a third of adults get less, according to the CDC.

In the new report, sleeping pill use started climbing among people in their 40s and 50s, with at least 5 percent resorting to the drugs. It was highest among those with more education -- and among women, with 5 percent reporting taking the pills, compared with 3.1 percent of men, the authors found.

That may reflect the strain of modern life, with people, particularly women, trying to juggle the growing demands of work and family, only to find it takes a toll on their sleep patterns, said Dr. Roneil Malkani, an assistant professor of neurology at the Northwestern Feinberg School of Medicine in Chicago.

“We know that insomnia is more prevalent among women than men,” he said. “I think that there are people who don’t get enough sleep because they have responsibilities and jobs and expectations.”

Just ask Chicago resident Yvonne Oby, 60, a manager at a legal firm who started taking Ambien CR in 2011 when sleep problems coincided with ramped-up work demands.

Ambien, a top-selling prescription sleeping pill, is among the many prescription drugs used by Americans seeking a good night's sleep.JB Reed

“We were in the beginning of doing a merger to become international,” recalled Oby, who found herself waking up at 1:30 a.m. -- and not being able to go back to sleep.

“I was at wit’s end. I would have a long, busy day ahead of me. I’m dealing with millions of dollars of billables,” she said.

Overall, the new study found that sleeping pill use increased with age, peaking at 7 percent in people older than 80, who often have chronic health problems that interfere with rest, Chong said. Researchers included use of hypnotic drugs and also antidepressants that have a sedative effect.

Use rose during the study period, climbing from 3.8 percent in 2005-06 to 4.5 percent in 2007-08 before dropping again. That uptick could reflect trouble sleeping during the worst part of the Great Recession, Chong said. The researchers are working on a larger study of trends over time and a study about how often people use sleep drugs, but the data aren't complete.

About 59 million sleeping pills were prescribed in the U.S. in 2012, up from about 56 million in 2008, according to IMS Health, which tracks drug data.

While the pills can provide solutions to sleep problems, experts such as Malkani caution that there are risks. The drugs are approved only for short-term use, even though some rely on them for months or years. A 2012 BMJ study found that people who took prescription sleeping pills were nearly five times as likely to die over 2½ years as those who didn’t.

Even when it’s not so dire, some people are allergic to the drugs, while others report bizarre behaviors, such as Ambien-fueled sleep-eating, sleep-driving, even sleep sex. In January, the U.S. Food and Drug Administration cautioned that women should take lower initial doses of Ambien, a brand name for zolpidem, because of the risk that next-day grogginess could interfere with driving and other activities.

Oby, the Chicago legal manager, said Ambien CR left her “in a stupor.” Worse, even when she didn’t take the drug for days, she could feel odd effects, such as the day she imagined her car was running at dangerously high speeds on the expressway.

“I was praying to God and crying, ‘Help me find the exit,’” she recalled. “It felt like I had no control.”

She stopped taking the controlled-release form of the drug on the advice of Dr. Hrayr Attarian of the Northwestern sleep disorders center. Instead, Oby now relies on tools of cognitive behavioral therapy -- a sleep log, exercises to help calm her mind -- plus a low-dose prescription of zolpidem, a drug called Intermezzo, which is formulated differently from Ambien and can help her sleep if she awakes in the middle of the night.

“I think that the awareness of the importance of sleep is still growing,” he said. “It’s important for people to get an adequate amount of sleep and to sleep well. It’s an investment for their function the next day.”